Welded sheet metal casings



y 1962 K. E. HlLFlNG ET AL 3,045,898

WELDED SHEET METAL CASINGS Filed Jan. 7, 1957 5 Sheets-Sheet 1 INVE TO 5% TTORNEY July 24, 1962 K. E. HlLFlNG ETI'AL WELDED SHEET METAL CASINGS 5 Sheets-Sheet 2 Filed Jan. '7, 1957 F/g. Z

TTORN EY y 1952 K. E. HILFING ETAL 3,045,898

WELDED SHEET METAL CASINGS Filed Jan. 7, 1957 5 Sheets-Sheet 3 IN T R! /vm% BY (1m July 24, 1962 K. E. HILFING ETAL 3,045,393

WELDED SHEET METAL CASINGS Filed Jan. 7, 1957 5 Sheets-Sheet 4 July 24, 1962 K. E. HILFING ETAL WELDED SHEET METAL CASING-S 5 Sheets-Sheet 5 Filed Jan. 7, 1957 INVEN OR: /(4o/ BY fl/% ATTORNEY 3,045,898 WELDIED SHEET METAL CASINGS Karl Erik Hil'fing, Gnllanget, and Nils Lindell, Stockhelm, Sweden, assignors to Atlas Copco Aktiebolag, Nacka, Sweden, a corporation of Sweden Filed Jan. 7, 1957, Ser. No. 632,700 9 Claims. ((11. 230234) This invention relates to welded sheet metal casings for reciprocating compressors. One object of the invention is to provide a Welded sheet metal casing for a reciprocating compressor in which the sheet metal pieces forming the casing are of simple shape and may be produced with inexpensive tools and simple machinery for formnig sheet metal. A further object of the invention is to provide a welded sheet metal casing in which the welds are disposed in such a manner that it is easy to position the sheet metal pieces and to weld them together. A further object of the invention is to produce a welded sheet metal casing for a reciprocating compressor in which air cooling of the compressor cylinders and other parts of the compressor may be produced in a simple and efficient manner. A still further object of the invention is to provide a welded sheet metal casing in which the cylinders and the crank shaft may be fitted with comparatively large clearances. Another object of the invention is to provide a welded sheet metal casing for a reciprocating compressor having two cylinders or pairs of cylinders in V-arrangernent and in which the easing forms one very rigid unit.

For these and other purposes we provide a welded sheet metal casing for a reciprocating compressor having two cylinder frames in V-arrangement on a crank case said casing being built up as a rigid unit by sheet metal pieces forming bottom, top, side walls and front and rear end walls of said crank case and outer and inner side walls and front and rear end walls of said cylinder frames, and by pairs of plates having openings for accommodating the cylinders welded in between said outer and innner side walls and said front and rear end walls of the cylinder frames.

In the accompanying drawings a welded sheet metal casing for a reciprocating compressor according to the invention is illustrated by way of example. FIG. 1 is an end view of a two cylinder two-stage V-type compressor having a casing according to the invention. FIG. 2 is a cross section of the compressor taken on the line 2--2 of FIG. 3. FIG. 3 is a side view of the compressor according to FIG. 1 and FIG. 4 is a longitudinal vertical section of the casing of the compressor taken on the line 4-4 of FIG. 1. FIG. 5 is a detail section on the line 5--5 of FIG. 1 of the cylinder frame of the low pressure cylinder of the compressor in FIG. 1, and FIG. 6 illustrates the arrangement of the intermediate cooler of the compressor according to FIG. 1. FIG. 7 is a sectional view taken on the line 77 of FIG. 4.

The illustrated compressor is a 90 V-type two-stage air-cooled compressor with two cylinders and sheet metal casing, The invention may, however, also be employed in single-stage V-type compressors and in compressors with two or more pairs of cylinders in V-arrangement.

The casing of the illustrated compressor consists generally of a crank case substantially in the shape of a cylindrical sheet metal body provided with front and rear end walls and formed in one piece with two cylinder frames in V-arrangement in which finned compressor cylinders are fitted. The casing is built up by a sheet metal piece 1 which forms a bottom 2, side walls 3 and 4 of the crank case as well as outer side walls 5 and 6 of the cylinder frames for the low and high pressure cylinders, further by a sheet metal piece forming a top wall 7 of the crank case and inner side walls 8 and 9 of 3,945,898 Patented July 24, 1962 the cylinder frames, furthermore a sheet metal piece forming at front end wall 10 of the crank case and front end walls 11 and 12 of the cylinder frames, and finally a piece forming a rear end wall 13 of the crank case and rear end walls 14 and 15, respectively, of the cylinder frames. The walls 10 and 13 are dished as is obvious from FIG. 4. Anchoring rings 16 and 17, respectively, are welded to the walls 10 and 13, respectively, to provide means for fitting the main crank shaft bearings 75 and 76, the bearing 76 being fitted in a carrier 77 bolted to the ring 16. The cylinder frames consist of the side and end Walls 5, 11, 8, 14 and 6, 12, 9, and pairs of plates 18, 19 for the low pressure cylinder and 20, 21 for the high pressure cylinder, respectively. The plates 18, 19 are welded to the sheet metal walls 5, 8, 11, 14 and the plates 20, 21 to the sheet metal walls 6, 9, 12, 15. The plates 18 and 19 are provided with circular openings 22 and 23 for accommodating a finned low pressure cylinder 24. Similarly, the plates and 21 are provided with circular openings 25 and 26 for accommodating a tinned high pressure cylinder 27. The cylinder 24 has a shoulder 28 which rests on the plate 19 and is provided with a packing 29 which forms a seal with the plate 13 and similarly the cylinder 27 has a shoulder 30 which rests on the plate 21 and a packing 31 forming a seal with the plate 20. Reference character 32 indicates the cylinder head of the low pressure cylinder and 33 indicates the cylinder head of the high pressure cylinder, said cylinder heads forming accommodation for conventional suction and delivery valves (not illustrated).

The sheet metal piece 7, 8, 9 forming the top of the crank case and the inner side walls of the cylinder frames is extended along the cylinder heads to form walls 34 and 35 which together with a front piece 36 and an extension 37 of the rear walls 13, 14, 15 and walls 38 and 43 form a substantially horizontally extending air intake case, which is divided by a vertical partition 39 and comprises a chamber 40 and a chamber 41. Between the air intake case and the top of the crank case an oil bath filter is provided which is generally indicated by 42.

The chamber 40 has an air intake opening 44 in the wall 36 and the chamber 41 has an opening 45 through which air may flow to suction valves in the low pressure cylinder head 32. The bottom plate 38 of the air intake case has openings 46 and 47 through which the chambers 40, 41 communicate with the oil bath filter 42. Said filter 42 consists of a sheet metal casing 48 of a shape fitting in between the walls 7, 8, 9 of the compressor casing and the walls 37, 38 of the air intake case. The lower portion of the oil bath filter is of V-shape and contains an adequate amount of oil 49 and the upper portion of the filter casing is divided by a partition 50 in two chambers containing filter elements 51 and 52. A sheet metal piece 53 forming the top of the filter casing 42 is provided with opening throats 54 and 55 corresponding to the openings 46 and 47 and O-ring packings 56 and 57 are provided around the throats 54, 55 to form air seals. The oil bath filter 42 is mounted from the front end of the compressor and eccentrics 58 are provided on a shaft 59 below the bottom of the filter to press it against the bottom 38 of the air intake case.

The wall 2 forming the bottom of the compressor crank case has an opening 69 and a dished sheet metal ring 61 is welded to the bottom at the edges of the opening and carries a dished cover 62 which together with the ring 61 forms an oil reservoir and cooler for the lubricating oil of the compressor.

The cylindrical walls 2, 3, 4 of the crank case are extended at the rear end of the casing and carry a structure similar to a squirrel cage comprising two rings 63 and 64 connected by axially extending guide plates 65. A cooling fan (not illustrated) which may preferably be formed on the flywheel of the compressor in conventional manner and a suitable motor coupling may be disposed within said squirrel cage structure. Cooling air is drawn through openings 66, 67 in the front end cylinder frame walls 11, 12 (FIG. 1), through the spaces around the cylinders in the cylinder frames and through openings 68, 69 to an intake chamber 70 of the cooling fan and from said intake chamber the cooling air is drawn through the fan and exhausted through a spiral housing 71 disposed around the squirrel cage 63-65. Cooling air is also drawn by the fan through an intermediate cooler 72 extending on top of the intake chamber 70 of the cooling fan between the cylinder heads 32 and 33 of the compressor. Furthermore, cooling air is drawn by the fan through a space 73 around the oil bath filter and opening 74 to the intake chamber 70.

The welded sheet metal casing 2-21 of the compressor forms a stiff and rigid body of low weight with smooth external surfaces and ample openings for permitting access to the moving parts of the compressor, which it is sometimes necessary to inspect, and which may easily be assembled into the casing or disassembled therefrom. In the illustrated and described embodiment of the invention the fan intake chamber and the squirrel cage structure are united with the combined crank case and cylinder frame casing to a unit which may be flanged together with a motor, but the squirrel cage structure and fan intake may naturally also be separate or formed as parts of the motor casing.

The above described sheet metal casing should be considered only as an example and various modifications of said casing may be made within the scope of the claims without departing from the principle of the invention.

What we claim is:

1. A sheet metal casing for a reciprocating compressor comprising a crankcase and a first and a second cylinder frame mounted in V-type arrangement on said crank case, said casing comprising four main sheet metal pieces welded together and one forming the bottom and the side walls of said crank case and the outer side Walls of the cylinder frames, a second forming the top of said crank case and the inner side walls of the frames, the third and fourth forming the end walls of said crank case and the frames, first and second pairs of plates having openings for accommodating compressor cylinders and being welded to said walls of the frames to complete the frames, and reinforcing rings welded to the end walls to form anchoring means for crank shaft main bearings.

2. A Welded sheet metal casing for a reciprocating compressor having a crank case, cylinder frames in V-arrangement on said crank case, cylinder liners in said cylinder frames, spaced top and bottom plates in said frames perpendicular to the axis of said liners, front end Walls of the crank case and the cylinder frames formed by a first sheet metal piece, rear end Walls of the crank case and the cylinder frames formed by a second sheet metal piece, opposed inner walls of the cylinder frames and a top wall of the crank case formed by a third sheet metal piece, remote outer Walls of the cylinder frames and side and bottom walls of the crank case formed by a fourth sheet metal piece, said top and bottom plates in the frames and said four sheet metal pieces being welded together to form a rigid unit.

3. A welded sheet metal casing as defined in claim 2 and two crank shaft main bearing supporting rings welded one to said front and one to said rear end wall of the crank case, respectively.

4. A welded sheet metal casing for a reciprocating compressor having a crank case and cylinders and cylinder frames in V-arrangement on said crank case, front and rear end Walls of the crank case and of said cylinder frames formed by a first and second substantially Y-shaped sheet metal piece, opposed inner Walls of the cylinder frames and a top wall of the crank case formed by a third substantially V-shaped sheet metal piece, remote outer walls of the cylinder frames and side and bottom Walls of the crank case formed by a fourth substantially V-shaped sheet metal piece having a substantially halfcylindrical'bottom portion, and transverse plates in the cylinder frames provided perpendicular to the cylinder axis and with openings for accommodating cylinder liners, all said sheet metal pieces being Welded together to provide a rigid unit.

5. A welded sheet metal casing as defined in claim 3 in which said sheet metal pieces forming the crank case end walls are dished.

6. A welded sheet metal casing as defined in claim 2 in which a substantially flat sheet metal air intake case is provided on top of the casing and Welded to said third sheet metal piece.

7. A welded sheet metal casing as defined in claim 6 in which a partition is provided in said air intake case dividing the case into two chambers, and in which an air filter is attached to and communicates with said chambers so that air may flow from one chamber through said filter to the other chamber.

8. A Welded sheet metal casing for a reciprocating compressor comprising a crankcase and two cylinder frames mounted in V-arrangement on said crankcase, a first main sheet metal piece forming bottom and sides of the crankcase and outer sidewalls of said cylinder frames, a second sheet metal piece forming the top of the crankcase and inner sidewalls of the cylinder frames, a third and fourth sheet metal piece forming, respectively, the front wall of the crankcase and cylinder frames and the rear Wall of the crankcase and frames, said pieces being welded together to form a rigid unit, finned compressor cylinders mounted in said frames, pairs of plates having openings for accommodating said cylinders and Welded to said frames and defining with them an air cooling jacket around each cylinder, a bottom opening in said crankcase, a sheet metal ring Welded to said crankcase and surrounding said bot tom opening, a sheet metal cover secured to said ring for closing said opening and air circulating means associated with said air cooling jackets for drawing air through said jackets.

9. A Welded sheet metal casing for a reciprocating compressor having two cylinders in V-arrangement mounted on a crankcase, said casing comprising a rigid fabricated unit, including a welded sheet metal crankcase and two welded sheet metal frames for enclosing said cylinders, said casing comprising a first sheet metal piece forming bottom and sidewalls of the crankcase and outer sidewalls of the cylinder frame, a second sheet metal piece forming a top wall of the crankcase and inner sidewalls of the cylinder frame and of general V-shape, a third sheet metal piece forming a dished front end wall of the crankcase and front end walls of the cylinder frames, a fourth sheet metal piece forming a dished rear end wall of the crankcase and rear end walls of the cylinder frames, each of said frames being provided with a pair of spaced plates disposed transversely to the cylinder axes, each pair of plates having aligned openings receiving the associated cylinders, said pairs of spaced plates being welded between front and rear and inner and outer sidewalls of the frames transversely to the cylinder axes and serving to complete the frames.

References Cited in the file of this patent UNITED STATES PATENTS 1,113,124 Jacobs Oct. 6, 1914 1,286,667 Leipert Dec. 3, 1918 1,287,359 Leipert Dec. 10, 1918 1,402,695 Wall Jan. 3, 1922 1,639,648 Carrey Aug. 23, 1927 1,801,395 Summers Apr. 21, 1931 1,846,656 Rayfield Feb. 23, 1932 (Other references on foliowing page) 5 UNITED STATES PATENTS Mutchler Apr. 2, 1935 Neal Feb. 11, 1936 McCune Jan. 25, 1938 Pavlecka May 10, 1938 Taylor July 13, 1948 Anderson Feb. 17, 1953 6 Medenus Feb. 28, 1956 Poux Mar. 20, 1956 FOREIGN PATENTS France July 11, 1925 France Aug. 28, 1933 Denmark Nov. 27, 1944 Germany May 24, 1954 

